EMPYEMA ALOK SINHA Department of Medicine Manipal College

EMPYEMA ALOK SINHA Department of Medicine Manipal College of Medical Sciences Pokhara, Nepal

EMPYEMA n presence of pus in the pleural space as thin as serous fluid n n so thick that it is impossible to aspirate even through a wide-bore needle empyema continues to be a significant cause of morbidity and mortality even in developed countries Associated with delay in the diagnosis or instigation of appropriate therapy ?

Aetiology • Mostly secondary to infection in a neighbouring structure - usually the lung bacterial pneumonias v T. B. v rupture of a subphrenic abscess through the diaphragm v infection of a haemothorax v Iatrogenic – following pleural aspiration v

Pathology n n Both layers of pleura are covered with a thick, shaggy inflammatory exudate pus is under considerable pressure & may rupture into a bronchus causing • bronchopleural fistula • pyopneumothorax track through chest wall with formation of • subcutaneous abscess • sinus

n empyema can heal • by eradication of the infection • obliteration of the empyema space n Early apposition of the visceral & parietal pleural layers are essential

Factors keeping pleura apart • air entering through a broncho pleural fistula • underlying disease in the lung, such as Bronchiectasis n bronchial carcinoma n pulmonary TB n prevents re-expansion n In these circumstances empyema become chronic. Surgical intervention required for healing

Clinical features n empyema should be suspected in patients with pulmonary infection • persistence or recurrence of pyrexia despite the administration of a suitable antibiotic n n Some times first definite clinical features may be due to the empyema itself Once an empyema has developed, two separate groups of clinical features are found

1. Systemic features Pyrexia, usually high and remittent Rigors, sweating, malaise and weight loss Polymorphonuclear leucocytosis, high CRP 2. Local features Symptoms: Pleural pain breathlessness cough and sputum – underlying lung disease copious purulent sputum – empyema ruptures into a bronchus Signs: Clubbing – regular feature in pyogenic infections Clinical signs of fluid in the pleural space Cause restrictive defect

Empyema necessitans n n A very rare condition in which an empyema goes undetected over a long period of time and progresses to the chronic stage Eventually the empyema erodes through the chest wall and spontaneously drains onto the surface of the body

INVESTIGATIONS

Radiological examination: indistinguishable from those of pleural effusion n Loculated fluid may be seen n When air is present in addition to pus pyopneumothorax horizontal 'fluid level' n

Homogenous density Loculated Loss of cardiophrenic angle Loss of lateral portion of diaphragmatic silhouette

Ultrasound n n n position of the fluid extent of pleural thickening single collection or multiloculated

CT n useful in assessing the underlying lung parenchyma and patency of the major bronchi

n n Aspiration of pus confirms presence of empyema performed using a wide-bore needle under Ultrasound or CT guidance pus frequently sterile when antibiotics have already been given Distinction between tuberculous and nontuberculous disease can be difficult and often requires pleural histology and culture

n n n intercostal tube with water-seal drain inserted in acutely ill ptient If initial aspirate – turbid or frank pus or loculated -tube should be put on suction (5 -10 cm H 2 O) and flushed regularly with 20 ml normal saline Pus culture & appropriate antibiotic given for 2 -4 weeks

n n n SURGICAL INTERVENTION Decompression of lung secured at an early stage by removal of all the pus from the pleural space to prevent visceral pleura becoming grossly thickened & rigid surgical intervention required when pus is thick or loculated Surgical 'decortication' of the lung required if gross thickening of the visceral pleura prevents re-expansion of the lung